The common chemical DEHP—found in carpets, flooring, upholstery and wires—and the industrial chemical PCB (polychlorinated biphenyl) 153—still found in foods despite a global ban—were the main causes for a decline in sperm quality.
Although sperm quality has declined by 50 per cent over the past 80 years, scientists haven't been entirely sure about the cause, although they've assumed it's been a reaction to environmental pollution.
But now they know it's much closer to home—and in the home, in fact. The missing clue was provided by researchers at Nottingham University who discovered that the family dog has also suffered a sharp decline in sperm quality. "The domestic dog is a sentinel or mirror for human male reproductive decline," said researcher Richard Lea.
The two pollutants were found in samples of human and dog sperm, which affected sperm motility and caused DNA fragmentation.